Response ofPemphigus betae(Hemiptera: Aphididae) and Beneficial Epigeal Arthropod Communities to Sugarbeet Plant Density and Seed-Applied Insecticide in Western Nebraska

Abstract

This study investigated the impact of a neonicotinoid seed-applied insecticide (Poncho Beta) and two plant densities (86,487 and 61,776 plants per hectare) on the sugarbeet root aphid (Pemphigus betae Doane), beneficial epigeal arthropods, and selected crop yield parameters in sugarbeet (Beta vulgaris L. var. vulgaris). Ground beetles and centipedes were the most commonly collected taxa during 2012 and 2013, respectively. Centipede, spider, and rove beetle activity densities were not affected by the seed-applied insecticide, whereas plant density had a marginal effect on centipede activity density during 2012. Ground beetle species richness, diversity, and evenness were also not impacted by the seed treatments. However, during 2013, ground beetle activity density was significantly higher in plots planted with untreated sugarbeet seeds due to the abundance of Bembidion quadrimaculatum oppositum Say. Sugarbeet root aphid populations were significantly higher in the untreated plots during both years. In 2012, sugarbeet tonnage and sugar yield were higher under the low plant density treatment, while higher sugar content was recorded from the seed-applied insecticide plots (2013). Seed-applied neonicotinoids and plant density had little impact on beneficial epigeal arthropod activity density. Seed treatment did result in decreased root aphid populations; however, these reductions were not sufficient to be considered as an adequate control. This limited aphid control likely contributed to inconsistent effects on yield parameters.

Comparing the Effects of Two Tillage Operations on Beneficial Epigeal Arthropod Communities and Their Associated Ecosystem Services in Sugar Beets

“…Residue cover left on the soil surface in zone tillage systems should favor beneficial arthropods, leading to increased prey and postdispersal weed-seed removal rates as a result of their higher abundance. Our target taxon for inquiry was the Carabidae, as they are reportedly sensitive to cultivation (Holland 2004) and commonly found in the sugar beet agroecosystem (Pretorius et al 2016). Therefore, carabids serve as bioindicators for monitoring the impact of cultivation on beneficial arthropods (Kromp 1999, Holland and Luff 2000).…”

Effect of plant protection on assemblages of ground beetles (Coleoptera, Carabidae) in sugar beet crops in four-year rotation

“…They are invaded by nematodes such as Heterodera schachtii, some beetles, e.g. Atomaria linearis, Chaetocnema concinna and larvae of the Elatheridae and Mellolontidae families, dipterans (Pegomya hyoscyami) and aphids (Aphis fabae) (Cooke 1991, Golizadeh et al 2016, Pretorius et al 2017, Sabbour & Solieman 2019, Wenninger et al 2019. Ground beetles can help reduce pest numbers, especially in fields where chemical protection is not applied.…”

Journal of Plant Protection Research

“…(Błaszkiewicz and Schwerk 2013;Fischer et al 2013) and the area neighboring cultivated areas (Leslie et al 2013). An important factor affecting the occurrence of beetles could be the density of the crop, because it will modify the microclimatic conditions (shading, humidity, temperature at ground level) in the area of cultivation (Akinkunmi et al 2012;Pretorius et al 2017). Due to their high sensitivity to pollution, ground beetles are often used as bioindicators of changes occurring in the soil environment (Rainio and Niemelä 2003).…”